The present invention relates to a method for manufacturing a brake carrier for a disc brake of a vehicle brake system, wherein the brake carrier has at least one guiding recess for guiding a brake pad in a guiding direction relative to a receiving region for a brake disc, wherein the method comprises the steps of manufacturing a brake carrier blank in a casting step and finishing the brake carrier blank by removing material for producing the at least one guiding recess. The present invention further relates to a brake carrier and to a disc brake having such a brake carrier.
Brake carriers of this kind in disc brakes are known from the prior art. In conventional brake carriers, in one machining step first the guiding recess is formed and subsequently, in a following machining step, the receiving region for the brake disc is machined in order to bring a disc clearance to a predetermined dimension. The forming of the guiding recess is generally effected by a chip-removal machining step, in which material is removed from the cast blank transversely to the receiving region of the brake disc, for example by means of a milling tool. The clear width of the receiving region for the brake disc which defines the disc clearance for a brake disc, i.e. the distance from one side of the brake carrier to the opposite side of the brake carrier across the receiving region of the brake disc, is likewise effected in an additional chip-removal machining step. In this step, a milling tool is moved in the receiving region along the inner region of the brake carrier. The disc clearance specifies a distance from one side of the brake carrier or the wall of the brake carrier to the opposite side face of the brake disc. The disc clearance must be chosen such that, in operation, a rotating brake disc which projects into the inner region of the brake carrier does not touch the brake carrier under all operating conditions.
In particular, a so-called disc runout and a lateral distortion of the brake disc under high thermal load, the so-called coning, must be taken into account and accordingly free spaces (disc clearance) provided on the brake carrier. Furthermore, this disc clearance must always be small enough to prevent, for example in the event of the actual friction pad of the brake pads being completely worn, the brake pads from slipping into the disc clearance during braking, since this would result in total failure of the brake. This means that the disc clearance should be less than the thickness of a backplate for brake pads. For safety, even 10% wear of the metal backplate of the brake pads must still not result in such slipping-in.
Since the disc clearance is set in the prior art by additional machining after a brake carrier has been manufactured as an unfinished cast part and after the guiding recesses have been made, disadvantages arise from the point of view of production. The additional machining of the receiving region for the brake disc for the purpose of setting the disc clearance is disadvantageous because any additional machining, besides a longer machining time, also increases the production costs.
The document DE 41 26 194 A1 discloses a fixed-caliper brake with a brake disc, in which supporting surfaces for the brake pads are machined in one milling operation to simplify the machining. In this case, the disc clearance can be additionally set in this operation, since the supporting surfaces project into the inner space of the brake carrier and the distance between two supporting surfaces lying opposite one another across the inner space defines the clear width. If the teaching from document DE 41 26 194 A1 is transferred to a brake caliper mounted in a floating manner on a brake carrier, however, guiding recesses have to be additionally provided, so that a further machining step is required, as described at the outset.